The present disclosure relates to a tip dresser configured to cut the tip ends of spot-welding electrode tips.
In automobile production lines, a spot welding technique has often been used to assemble a car body. According to the spot welding technique, however, as the welding work is carried out over and over again, an increasingly thick oxide film is gradually deposited over the tip ends of the electrode tips. If the welding process were carried out with no redressing done on those thickened tips, then the quality of resultant welded portions would deteriorate. For that reason, such thickened tip ends of the electrode tips need to be regularly cut by a tip dresser to remove the oxide film.
Meanwhile, the chips to be shaved off while the electrode tips are being cut by the tip dresser may scatter and be deposited on a drive unit or any other part of another machine. In that case, the load on the drive unit increases, and in a worst-case scenario, increases so much as to cause a breakdown of the machine. Thus, to avoid such an unwanted situation, a portion of the tip dresser that performs the cutting work is enclosed in a cover case to prevent such chips from scattering to the environment.
For example, the tip dresser disclosed in Japanese Unexamined Patent Publication No. 2004-202504 includes a rotary cutter, of which the rotation axis extends vertically. The top and bottom surfaces of the rotary cutter are respectively provided with a pair of recessed receivers which receive the tip ends of electrode tips so that the center axis of the electrode tips agrees with the rotation axis of the rotary cutter. The tip dresser is configured to cut the respective tip ends of the electrode tips with a pair of cutting edges provided for the rotary cutter by rotating the rotary cutter with the tip ends of the pair of electrode tips, which are arranged to face each other on both sides of the rotary cutter in the rotation axis direction thereof, received in those recessed receivers. In addition, a pair of cover cases which respectively cover the top and bottom surfaces of the rotary cutter are respectively arranged over and under the rotary cutter so as to prevent chips to be shaved off through the cutting work with the rotary cutter from scattering.